Stringer-releasing shore assembly for a concrete slab form installation



March 4. 1969 F. BOWDEN ET AL v 3,430,910

STRINGER-RELEAS ING SHORE ASSEMBLY FOR A CONCRETE SLAB FORM INSTALLATION Filed Feb. 6, 1967 Sheet of 5 INVENTORS.

GEORGE F. BOWDEN RICHARD T. DAGIEL March 4. 1969 v G. F. BOWDEN ET AL 3,430,910

STRINGER-RELEASING SHORE ASSEMBLY FOR A CONCRETE SLAB FORM INSTALLATION Filed Feb. '6, 1967 Sheet 2 of5 INVENTORS.

GEORGE F. BOWDEN RICHARD T. DAGIEL March 4. 1969 G, ow ET AL 3,430,910

' STRINGER-RELEASING SHORE ASSEMBLY FOR A CONCRETE Y SLAB FORM INSTALLATION Filed Feb. 6. 1967 Sheet 3' of o- 28 w 6 3 p" 'lel so 30 I A! 1 o 5 2e 24 44 7a 46 26 N FIG. 3 2 FIG. 4

l2 [l2 5o F. as

/66 v v 50 w l/JJ 42 INVENTORS.

GEORGE F. BOWDEN RICHARD T. DAGIEL March 4. 1969 G. F. BOWDEN ET AL 3,430,910

STRINGER-RELEASING SHORE ASSEMBLY FOR A CONCRETE SLAB FORM INSTALLATION Filed Feb. 6, 1967 v Sheet 4 of5 FIG. 8

76 76 m FIG. 9

46 9 [78 (I04 I \|9Q [84 INVENTORS.

GEORGE E BOWDEN RICHARD T. DAGIEL By v March 4, 1969 'G, F. BOWDEN ET AL 3,430,910

STRINGER-RELEASING SHORE ASSEMBLY FOR A CONCRETE SLAB FORM INSTALLATION Filed Feb. 6, 1967 Sheet 5 of 5 H6. ll

INVENTORS.

GEORGE F BOWDEN RICHARDT. AGIEL 1 By w,

United States Patent 3,430,910 STRINGER-RELEASING SHORE ASSEMBLY FOR A CONCRETE SLAB FORM INSTALLATION George F. Bowden, Northbrook, and Richard T. Dagiel,

Elk Grove Village, 11]., assignors to Symons Mfg. Company, Des Plaines, Ill., a corporation of Delaware Filed Feb. 6, 1967, Ser. No. 614,319 US. Cl. 248354 2 Claims Int. Cl. F16m 13/00 ABSTRACT OF THE DISCLOSURE A supporting shore for a concrete slab, having a vertically shiftable stringer-supported member, which in its raised position, normally supports the stringer and associated panels during hardening of the concrete, and which, in its lowered position, releases the stringer so that the latter may be removed from beneath the slab at an early date and without waiting for the concrete to become fully hardened.

The present invention relates generally to concrete building construction and has particular reference to a novel shore assembly which is designed for use in releasably supporting a pair of adjacent horizontal stringers in their proper end-to-end relationship of alignment in a concrete floor slab form installation preparatory to and during a concrete pouring operation as well as after the concrete has been poured and up until such time as the concrete has become sufiiciently set or hard that it is considered safe to remove the stringers.

Specifically, the shore assembly of the present invention is designed for use in connection With a system of concrete building erection which is known in the building industry as a Slab-Shore System and involves the use of several novel major items such as special shores and stringers for supporting in proper position the horizontal slab-forming panels of the system, and in addition, novel minor items such as supporting brackets, shore-to-stringer connections, grout seals, locking devices, fill-in pieces (Where necessary) for making up either longitudinal or transverse odd dimensions, and special tools for installing and removing such minor items. This system of building erection is disclosed in, and forms the subject matter of, United States Patent No. 3,130,470, granted on Apr. 28, 1964 and entitled Concrete Wall Form Installation.

The principle feature of a so-called Slab-Shore System as disclosed in the aforementioned patent resides in the ability progressively to remove localized groups of slabforming panels as soon as the green concrete slabs thereon have gained sufficient strength to justify panel removal without having to resort to such prolonged curing of the concrete slabs as will enable the stringers and shores in the immediate vicinity to be removed for panel-releasing purposes. This panel-releasing feature of a Slab-Shore System is made possible by the use of a special form of stringer assembly having vertically movable ledge-type supporting members which are adapted to have the ends of the horizontal slab-forming panels rest thereon and are capable of being lowered or dropped throughout a limited vertical extent in order to afford sufficient clearance that the panels may be taken from the installation or system without necessitating relief of the supporting pressure which is exerted by the stringers and shores upon the superjacent concrete slabs. In this manner, the usual period, sometimes amounting to as much as ten days, during which the concrete must remain supported before panel removal can be effected has been shortened to a matter of twenty-four hours in many instances and, at the most, forty-eight hours. The particular panel releasing stringer which has resulted in such early release of the slab-forming panels is disclosed in, and forms the subject matter of, United States Patent No. 3,052,008, granted on Sept. 4, 1962 and entitled Panel-Supporting Stringer Assembly for a Concrete Floor Slab, the application for such patent having been filed as a division of the application for said Patent No. 3,130,470. A suitable stringer supporting shore assembly for use in a Slab-Shore System is disclosed in, and forms the subject matter of, United States Patent No. 3,130,950, granted on Apr. 28, 1964 and entitled Shore Assembly for Concrete Floor Slabs, the application for such patent having been filed as another division of the application for aforesaid Patent No. 3,130,470.

The stringer supporting and releasing shore assembly of the present invention is similar in its purpose to that of said Patent No. 3,130,950 in that it serves as a medium for releasably supporting the associated stringers in endto-end relationship. It dilfers, however, from the shore assembly of the last mentioned patent in that is makes possible the removal of the two associated stringers at an earlier time than has heretofore been possible, such time being coincident with the time when the concrete has become sufficiently cured as to justify removal of the stringers, the removal taking taking place without necessitating relief of the supporting pressure that is exerted by the shore assembly.

Heretofore, when large area concrete floor slabs are concerned, it has been possible to effect a progressive release of localized groups of stringers by first withdrawing the shore assemblies which support them and then, immediately thereafter, positioning the assemblies back in place for further slab supporting purposes. Alternatively, auxiliary temporary shore-type supports have been applied in the vicinity of those to be removed for stringerreleasing purposes. Not only do such procedures involve high labor costs, but the temporary and progressive removal of the shore assemblies as well as permanent removal of the stringers places an undue and premature stress upon the concrete which has not yet attained full strength and frequently results in the creation of small hair-like cracks and other regions of Weakness which permanently weakens the floor slab undergoing formation.

The Slab-Shore System to which reference has heretofore been made and which is comprehended by aforementioned Patent No. 3,130,470 employs shore assemblies (see said Patent No. 3,130,950) having special means whereby they may interlock with the ends of the adjacent stringers which they support. However, the shore assembly of said Patent No. 3,130,950 makes no provision for releasing the two stringers which it supports except by withdrawal thereof from the concrete slab form installation.

The novel stringer-releasing shore assembly of the present invention is designed as an improvement over the shore assembly that is shown and described in all three of the aforementioned patents in that it is provided with drop-type supports or ledges which interlock with the adjacent ends of the associated stringers in the same manner as the shore assembly over which it is designed as an improvement, but which, when lowered or dropped throughout a limited degree, afford the necessary clearance for removal of the stringers from which, of course, the associated slab-forming panels have previously been removed. The shore assembly of the present invention thus extends the usefulness of the Slab-Shore System" which is shown and described in said Patent No. 3,130,- 470. The provision of such a shore assembly constitutes the principal object of the present invention.

Numerous other objects and advantages of the invention, not at this time enumerated, will readily suggest themselves as the nature of the invention is better understood from a consideration of the following detailed description or specification.

In the accompanying five sheets of drawings forming a part of this specification, one illustrative embodiment of the invention is shown.

In these drawings:

FIG. 1 is a fragmentary top perspective view of a typical concrete floor slab installation involving the formation of a horizontally disposed concrete floor slab, such view showing a number of the stringer releasing shore assemblies of the present invention operatively in use in the installation;

FIG. 2 is an enlarged fragmentary perspective view illustrating, in exploded fashion, one of the improved shore assemblies and its two associated horizontal stringers;

FIG. 3 is a fragmentary side elevational view showing the shore assembly of FIG. 2 with the adjacent end regions of the two associated and aligned stringers operatively installed thereon;

FIG. 4 is a fragmentary side elevational view similar" to FIG. 3 but showing the stringer-supporting cradle member in its lowered or dropped position preparatory to removal of the associated stringers from the concrete floor slab form installation;

FIG. 5 is a fragmentary side elevational view similar to FIG. 4 but illustrating the manner in which one of the associated stringers is released from the shore assembly after dropping of the vertically movable stringer-supporting cradle member;

FIG. 6 is a vertical sectional view taken on the line 6-6 of FIG. 5;

FIG. 7 is an enlarged fragmentary side elevational view of the improved shore assembly constituting the present invention;

FIG. 8 is a top plan view of the shore assembly of FIG. 7;

FIG. 9 is an enlarged horizontal sectional view taken on the line 9-9 of FIG. 7;

FIG. 10 is an exploded perspective view of the twopart separable clamp assembly that is employed in connection with the present invention; and

FIG. 11 is an enlarged vertical sectional view taken on the line 11-11 of FIG. 7.

Referring now to the drawings in detail and in particular to FIG. 1, there is disclosed in this figure a typical concrete floor slab installation involving the horizontal supporting surface for a concrete floor slab resulting from the pouring of wet concrete on such surface. The entire installation is designated in its entirety by the reference numeral 10 and involves a series of laterally spaced, vertically disposed shore assemblies 12 which embody the present invention and will hereinafter be referred to siniply as shores. The upper ends of these shores serve to support a plurality of series of longitudinally extending, horizontal stringers 14 and such stringers, in turn, support a plurality of series of transversely disposed, horizontal 4 slab-forming panels 16, the end edges of the latter resting on, and being supported by, the stringers.

The floor slab which is formed by pouring concrete on the upper planar surface that is afforded or formed by the panels 16 and also by the uppermost portions of both the shores 12 and the stringers 14 may, for example, constitute the first poured lowermost slab of a vertical series of vertically spaced, superimposed slabs subsequently to be poured in a multi-story building structure, the various slabs forming the bases for the floor and ceiling installations of the building. In such a case, the shores 12 will be set up in the usual manner of shore installation on sills or other supporting elements which are positioned on the ground or other foundation surface and serve to prelocate the various vertically disposed shores. If the supporting surface that is represented by the upper faces of the panels 16 is 'for the purpose of receiving poured concrete to produce one of the upper floor slabs, then the aforementioned supporting elements will be installed on the last formed concrete floor slab. It will be understood that the various shores 12 may be cross-braced in any suitable manner by struts or the like, such crossbracing being omitted herein since it forms no part of the present invention.

The concrete floor slab installation 10 is merely illustrative of a typical installation in which the shores 12 are arranged in three spaced apart, longitudinally extending rows and with the panels 16 having their own longitudinal direction extending transversely of the installation between the adjacent parallel stringers 14. The panels 16 are conventional, reuseable, prefabricated Steel-Ply panels of the type which is shown and described in the three aforementioned patents. Such panels are manufactured and sold by Symons Mfg. Company of Des Plaines, Illinois and are in the form of shallow rectangular box-like structures of tray-like design. Each panel includes a plywood facing 18 which is bounded by marginal studding 20 in the form of a rectangular steel frame. The stringers 14 are also of special design and are manufactured and sold by said Symons Mfg. Company, each stringer being in the form of an I-beam (see FIG. 2) including a horizontal top flange 22, a horizontal bottom flange 24 and an interconnecting vertical web portion 26. Movably supported on opposite sides of the web portion of each stringer 14 are two ledge-type, panel-supporting members in the form of anglepieces 28 (see FIGS. 2 to 6, inclusive) which are normally held in the raised position in which they are shown in FIG. 3 but which are capable of being lowered to the position in which they are shown in FIGS. 4, 5 and 6 for panel releasing purposes. Nut and bolt assemblies 30 which ride in arcuate slots 32 in the web portions 26 of the stringers 14 are provided for clamping the angle pieces 28 in their raised or panel-supporting position. Raised or upstanding protuberances 34 on the horizontal flanges of the anglepieces 28 normally lie behind the lower rim portions of the end parts of the studding 20 when said end parts rest on the anglepieces, and prevent endwise shifting of the panels when the anglepieces are in their lowered positions. In FIG. 2, the panels 16 have been omitted in the interests of clarity since the present invention relates to the novel construction of the shore .12 and to the novel releasable interlock connection between the shore and the adjacent ends of the two stringers 14 which are associated therewith and supported thereby. It will be understood, however, that when the panels 16 are operatively in stalled upon the stringers 14 in the concrete floor slab installation as shown in FIG. 1, the upper concrete-receiving surfaces of the plywood facings 18 will lie in a common plane which passes through the extreme flat upper ends of the shores 12 and through the upper flanges 22 of the stringers 14, all in the manner set forth in detail in the three aforementioned patents. This common plane which defines the underneath surface of the poured concrete floor slab is indicated by the dotted line P in FIG. 4.

Referring now to FIGS. 2 to 10, inclusive, and in particular to FIG. 2, the improved shore assembly or shore 12 of the present invention involves in its general organization an adjustable base part which is comprised of any desired number of telescopic tubular sections, two such sections being shown at 40 and 42 (FIG. 1); and an upper part in the form of a shore head 44. The shore 12 is similar in many respects to the shore assembly of aforementioned Patent No. 3,130,950, is similarly disposed in the concrete floor slab installation 10, and differs from the earlier shore assembly solely in the construction of the shore head 44. Whereas the shore head of the earlier shore assembly makes no provision for releasing the stringers 14 with which it is associated, the present shore head 44 is provided with a vertically shiftable stringersupporting cradle member 46 which, when in the elevated position in which it is shown in FIGS. 2 and 3, serves to maintain the stringers in their operative panel-supporting position and, when in the lowered position in which it is shown in FIGS. 4, 5 and 6, allows the stringers to be removed from beneath the partially cured, but nevertheless self-supporting, superjacent concrete floor slab.

The shore head 44 is comprisedof but relatively few parts and these include the aforementioned vertically movable cradle member 46 (see FIGS. 7, 8 and 9), a rotatable tubular body portion 50, and an inner extensible and retractible post section 51 which, in effect, constitutes an uppermost shore section in that it seats upon the section 42 of the adjustable base part of the shore. The upper end region of the post section 51 is provided with an external screw thread 52 for mating engagement with an internal screw thread 53 which is formed on the inner periphery or surface of the body portion 50 and is coextensive therewith. The externally threaded upper end region of the post section 51 is of slightly increased diameter so that when the post section is threaded into the rotatable tubular body portion 50 an appreciable distance there will be an overhang of the internal screw thread 53, thus establishing on the body portion a depending apron 54 which encompasses and is slightly spaced from the cylindrical side wall of the post section 51. The lower end of the post section 51 is formed with a reduced pilot section 55 (see FIG. 11) which projects into the upper end of the shore section 42 and establishes a downwardly facing annular shoulder 56 which seats on the upper rim of said-shore section 42. A hole 57 in the pilot section 55 of the post section 51 registers with a hole 58 in the shore section 42 and both of these holes are adapted when in registering relation to receive therein a conventional fastening pin 59 (see FIG. 11) which prevents relative turning movement of the post section 51 and the shore section 42.

From the above description, it will be apparent that by rotating or turning the body portion 50 in one direction or the other with respect to the fixed post section 51, elongation or shortening, as the case may be, of the shore 12 as a Whole may be effected. The upper end of the body portion 50 is provided with a combined end closure and bearing plate 60, the rim portion of which extends downwards and overhangs the upper end of the body portion 50 as indicated at 61 for a purpose that will be made clear presently. A vertically disposed elevation post 62 has its lower end projecting through a hole 63 which is centrally formed in the combined end closure and bearing plate 60' and is fixedly secured for rotation bodily with the body portion 50 by means of a horizontal through bolt 64 which projects diametrically across the upper end of said body portion and passes through the lower end of the post 62. The upper end of the elevation post 62 is squared as at 65 for reception of a suitable torque-applying tool such as a wrench by means of which the post, and consequently, the body portion 50, may be turned as a unit, thus making it possible to effect a relatively fine adjustment of the height of the body portion for slab-levelling purposes, the adjustment being made by a Workman operating from above the panels 16. A similar adjustment may be made by a workman operating from below the level of the panels by reason of three torque brackets 66 which are welded to the lower end region of the body portion 50, these brackets being capable of cooperation with a suitable torque tool such as a spanner wrench or the like (not shown).

The elevation post 62 is provided with a radial flange 67 a short distance above the level of the combined end closure and bearing plate 60 and this flange constitutes a limit stop for a rotatable bearing shoe plate 68 through which the lower end portion of the post loosely projects. Such bearing shoe plate rests on the combined end closure and bearing plate 60' and constitutes a bottom closure plate for a tubular upstanding box-like housing 69 which is of rectangular configuration in cross section and encloses or houses the elevation post 62. The rectangular upper rim of the housing 69 is open and is adapted to be closed by a removable slab-supporting filler plate 70 which is adapted to rest upon the upper rim of the housing 69 and lie within the common plane P (FIG. 4) which, as previously stated, defines the underneath surface of the concrete floor slab undergoing formation. Spring fingers 72 serve releasably to retain the filler plate 70 in position at the top of the shore assembly. When said filler plate is removed, access is provided to the upper squared end of the elevation post 62.

The cradle member 46 is essentially a unitary structure and is comprised of welded parts including a central sleeve member 74, two triangular webs 76 which project radially outwardly from the sleeve member on opposite sides thereof, and a pair of cradles proper 78 (see FIGS. 2 and 7) which are carried at the upper ends of the webs 76. Each cradle proper 78 is in the form of a short length of channel stock and consists of a horizontal bottom plate 80 and upstanding side flanges 82. Two upwardly tapered posts 84 in the form of rivet shanks project upwardly from the bottom plate 80 of each cradle proper and are adapted to receive thereover cooperating holes 86 which are formed in the adjacent end portion of the bottom flange 24 of the adjacent or associated stringer 14, that is, the particular stringer which is supported by said cradle proper. Pairs of closely spaced ears 90 project outwardly from the opposite sides of the housing 69 and are adapted to receive therebetween the adjacent extreme end edge portions of.

the vertical web portions 26 and the stringers 14. Notches 91 are cut in these extreme end edge portions of the web portions and serve a function which will be made clear presently.

The central sleeve member 74 of the cradle member 46 loosely surrounds the body portion 50' of the shore head 44 and is vertically shiftable on said body portion between the raised or elevated position wherein it is shown in FIGS. 2, 3 and 11, and the lowered position wherein it is shown in FIGS. 4, 5 and 6. Said central sleeve member 74 is adapted to be releasably supported in its raised position by means of a two-part separable clamp assembly 92, the details of which are clearly shown in FIG. 10. Such clamp assembly comprises arcuate counterpart sections 94 and 96 having at certain opposed ends thereof mating ears 98 which are capable of connection by a nut and bolt assembly 100, and having at their other opposed ends similar mating ears 102 which are capable of connection by a conventional wedge and bolt assembly 104. The clamp assembly 92 thus assumes the form of a two-part separable collar which is adapted to surround the body portion 50 of the shore head 44 immediately below the lower end of the sleeve member 74 when the latter is in its raised position and the lower edge of the clamp assembly is supported on the upper edges of two reaction plates 106 which are welded to the outside face of said body portion 50 of the shore head 44 in diametrically disposed relationship. Upon removal of the clamp assembly 92 as shown in FIGS. 4, and 6, the sleeve member 74 and its associated parts will fall by gravity to its lowered position and come to rest upon the upper edges of said two diametrically disposed reaction plates 106.

Referring now to FIGS. 3 to 6, inclusive, wherein the manner in which the shore assembly 10 of the present invention is manipulated in order to release the associated stringers 14 from any given concrete floor slab installation such as that illustrated in FIG. 1, the disclosure of FIG. 3 represents the condition of one of the shore assemblies or shores 12 when it is in its operative position beneath a poured floor slab which has hardened sufliciently to justify removal of the two associated aligned stringers 14 which it serves to support. The ends of the slabforming panels 16 are shown as being operatively supported on the anglepieces 28 and the adjacent ends of the stringers 14 are held in position by the ears 90' which straddle the web portions 26 of the stringers. The notches 91 are slightly above the level of the ears 90 and, thus, are consequently out of register therewith so that the ears maintain the stringers against lateral shifting. The clamp assembly 92 is disposed on the short head 44 and rests upon the two welded-in-place reaction plates 106 so that the vertical movable cradle member 46 is maintained in its upper position and holds the two adjacent stringers in their operative slab-supporting relationship with the top flanges 22 thereof at slab level as previously described. The filler plate 70 is in position within the rim region of the box-like housing 69 and likewise is at slab level. The anglepieces 28 are in their raised position to hold the panels 16 in slab-supporting relationship with their plywood facings 18 at slab level.

It will be understood that, in accordance with Symons Mfg. Companys Slab-Shore System as shown and described in aforementioned Patent No. 3,130,470, after the freshly poured concrete slab has become sufficiently set or hard to justify removal of the panels 16, the time required being a matter of approximately twenty-four hours under favorable conditions, the anglepieces 28 will be lowered to release the panels and permit their withdrawal from the installation. Thereafter, when the concrete of the slab has become further hardened so as to justify removal of the stringers, the vertically shiftable or movable cradle member 46 is manipulated to release the stringers. The manipulation of the cradle member is illustrated in FIG. 4 wherein the two-part separable clamp assembly 92 has been removed from the shore head 44 so that the cradle member 46 assumes its lowermost position with the lower rim of the tubular body portion 50 resting directly on the upper horizontal edges of the two aforementioned welded-in-place reaction plates 106. With the cradle member thus lowered, the adjacent ends of the stringers 14 likewise are lowered but the level of the tubular box-like housing 69 remains undisturbed and the filler plate 70 continues to lend the necessary support to the concrete slab. It will be observed that with the adjacent ends of the stringers 14 thus lowered as shown in FIG. 4, the level of the notches 91 is slightly below the level of the ears 90 so that these ears continue to straddle the Web portions 26 of the stringers and maintain the latter against lateral shifting. The upstanding posts '84- continue to prevent axial or longitudinal shifting of the stringers so that the latter remain captured, so to speak, against involuntary dislodgement from the concrete floor slab installation.

The next step in the stringer-removal operation is for the operator or operators to raise the level of the adjacent ends of the stringers 14 until the notches 91 and cars 90 are in horizontal register with one another. Such a condition is illustrated in the right half of FIG. 5. At this time, the level of the bottom flanges 24 of the stringers is slightly above the level of the posts 84 so that by causing the stringers to become laterally inclined as shown in FIG. 6, the web portions 26 of the stringers will move away from the ears 90. Thereafter, the stringers may be lifted from the cradles proper 78 and thus freed from the concrete floor slab installation. It will be understood that at the remote or far ends of the stringers 14 in the vicinity of the next adjacent shore assemblies in the installation, a similar stringer-releasing operation will either be effected simultaneously or it will have previously been resorted to so that the stringers 14 will have substantially complete freedom of movement in the manner outlined above.

From the above description, it will be appreciated that by means of the present shore assembly with its vertically shiftable cradle member 46, the shoring support for the superjacent concrete "floor slab is at no time disturbed. The solid column of metal extending from the floor or base foundation surface upwardly through the various shore sections 40 and 42, the post section 51, the tubular body portion 50 of the shore head 44, the tubular boxlike housing 60, and the filler plate remains at all times eifective to support the slab. No temporary or auxiliary shoring is required and the original shoring part of the installation remains effective to support the floor slab during early panel-removal operations and subsequent stringer-removal operations.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. For example, it is within the purview of the present invention to dispense entirely with the elevation post 62 and, otherwise, to make no provision for slight adjustments of the floor slab. If desired, the drop-cradle construction which constitutes the subject matter of the present invention may be embodied in a simplified form of shore assembly consisting simply of a single shore post, or a sectional shore post, the drop-cradle being operatively installed on the same in the upper regions thereof. Therefore, only insofar as the invention is particularly pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what we claim as new and desire to secure by Letters Patent is:

1. A stringer-supporting shore comprising an elongated generally cylindrical post adapted to be positioned vertically in a concrete floor slab installation with its lower end supported on a foundation surface and its upper end in slab-supporting relationship, a cradle member movably mounted on said post in the upper region thereof for limited vertical displacement between a raised and a lowered position, said cradle member comprising a tubular sleeve loosely encircling the post and a pair of stringer supports extending laterally from said tubular sleeve in opposite directions and adapted to receive thereon the adjacent end portions of a pair of aligned panelsupporting stringers, means on said post establishing an upwardly facing reaction shoulder upon which the lower rim of the tubular sleeve is normally adapted to rest to determine the lowered position of the cradle member, and a removable reaction member adapted for interpositioning between said lower rim of the tubular sleeve and said reaction shoulder and having an effective vertical width which establishes the raised position of the cradle member, said post being of a sectional nature and including an upper tubular non-rotatable section, a shore head on said upper section and comprising a rotatable tubular body portion telescopically and threadedly received over said upper section, an elevation post fixedly secured to said tubular body portion in coaxial relationship and projecting upwardly therefrom, the upper end of said elevation post being non-circular in transverse cross section for cooperation with a torque-applying wrench, a non-rotatable tubular housing coaxial with said rotatable tubular body portion, encompassing said elevation post and slidably supported on the upper end of said body portion, and an imperforate filler plate removably clos ing the upper end of said tubular housing, said upwardly facing reaction shoulder being formed on the rotatable tubular body portion.

2. A stringer-supporting shore as set forth in claim 1 and wherein the removable reaction member is in the form of a generally circular, two-part, separable clamp adapted loosely to encircle said body portion above the level of said reaction shoulder With its lower rim opposing the latter and with its upper rim opposing the lower rim of the tubular sleeve.

References Cited UNITED STATES PATENTS 1,540,753 -6/ 1925 Birch 248-354 3,052,008 9/1962 Bowden et al. 249192 5 3,130,470 4/1964 Bowden et al. 249192 3,239,188 3/1966 Gostling 249-21O 'ROY D. FRAZIER, Primary Examiner.

10 I. FRANKLIN FOSS, Assistant Examiner.

US. Cl. X.R. 

